Hitachi Medical Corporation

Hiromichi Shimizu

Tetsuhiko Takahashi

Shigeru Watanabe

Hirotaka Takeshima

A magnetic resonance imaging apparatus is provided with a sequencer for executing a rapid imaging sequence of up to 100 ms at a full scan, a parallel measurement system for executing a partial encoding measurement in which the number of phase encoding operations performed for the measurement is reduced, an image processing system for reconstructing images from the information obtained though parallel measurements and composing reconstructed images of a plurality of areas to make one image, a display system for displaying the obtained images at a rate of 50 frame/second or more, and an image renewal system for taking in coordinate information of the cross-section to be imaged from position and pointing devices at intervals of about 0.1 second, and renewing the cross-section to be imaged in real time. Thus, imaging on the cross-sections indicated by a device can be performed in real time with high spatial and high time resolution.

Magnetic resonance imaging system

A burst wave is applied as an RF magnetic filed in order to excite nuclei of hydrogen, and also a oradient magnetic field along a readout direction is applied so as to excite magnetization in a stripe shape. Thereafter, while a magnetization-inverting RF magnetic field pulse for selecting a slice is applied and a readout gradient magnetic field is applied, a signal is measured. At this time, a time instant when a spin echo is produced is made different from a time instant when a gradient magnetic field echo is produced, so that a phase rotation made by a chemical shift may be reflected on to a signal. The MR signal is processed by a 2-dimensional Fourier-transform, and a phase distribution is calculated from both a real part and an imaginary part of complex data after the 2-dimensional Fourier-transform. Then, this calculated phase distribution is converted into a temperature change so as to display the temperature change. A temperature change in a diseased portion in connection with IVMR can be monitored in real time.

Magnetic resonance image diagnosing apparatus

A plurality of signal acquisition steps to are executed continuously in succession to an inversion longitudinal magnetization generation step for generating inversion magnetization by applying inversion RF pulses to an object. Similar process steps are iterated in another inversion longitudinal magnetization step in a slice non-selecting mode, and the difference is determined between image data acquired by the first signal acquisition steps to and image data acquired by the second signal acquisition steps to to acquire a perfusion image. In this instance, the mode of applying the gradient magnetic field is made different in each signal acquisition step, and images of a plurality of slices are acquired. The process steps described above are iterated while the correspondence relation between an inversion time TI and a selected slice is changed. An image having different inversion times can thus be acquired within a short time for a plurality of slices. Consequently, an image reflecting the time change of perfusion and having a high diagnostic value can be acquired over a broad range.

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Tokyo, Japan

Hiromichi Shimizu